Having worked out what I have bought and fixed the loose stock, it’s time to try to work out why my €20 AEG won’t shoot. It didn’t come with batteries, but when I tried fitting the battery pack from my Umarex G36C, nothing happened when I pulled the trigger. The 7.4v Umarex battery is less powerful that the recommended 9.6v battery for this King Arms replica, but even so, it should operate. Clearly something is wrong.
I have to admit that I hate working with anything electrical. I have restored a fair number of elderly motorcycles over the years, and the bit I always dreaded was trying to sort out electrical gremlins. The crisply lined wiring diagrams never bore much resemblance to the rat’s nest of mismatched wires and soggy insulating tape that I found under the tank of most bikes. However, here I’m happy to report that the problem is fairly obvious, even to me.
The battery lives inside the vertically split front foregrip. To remove it, the sprung rear plate is held down and then one or both halves can be lifted off. Looking closely at the end of the Mini-Tamiya connector reveals that the wires have been fairly crudely bodged into the metal connectors. A couple of strands of one are even touching the other wire, clearly causing the connection to short-out.
It doesn’t take long to remake new, neater and more effective connections. I plug in the battery pack and it shoots in both semi and full auto modes. Hurrah! I haven’t yet tried it with BBs, but this AEG is certainly operational now.
There is nothing else terribly wrong with this replica (and the red-dot sight works too – it just needed a new battery!) so all that’s left to do is to try to make it look a little better. I begin by stripping it down. To do this, you only need to remove a single pin, arrowed below.
This then allows the barrel assembly and upper receiver to be slid off to the front, being careful to guide the battery wires into the trough in which they sit.
The inner barrel and hop up can then be slid out to the rear and the inner plate that covers the ejection port can be removed.
This disassembly probably isn’t essential, but it does give me a chance to check the internals. Nothing seems to be obviously broken or worn, the inner barrel looks straight and in good condition, the hop-up works as it should and I can’t see any other issues. It’s now time to start thinking about how to improve the way this rather tired AEGs looks. There is a fair amount of corrosion on metal parts including the ejector port cover, the handguard front plate and the collar that stabilizes the buffer tube.
All the metal parts are removed, sanded to remove rust and sprayed with a can of acrylic satin black that I have in the shed.
Then it gets cleaned thoroughly in warm water with a little washing-up liquid in it. This also gets rid of all the stickers. Finally, I go over all the plastics with a little silicon spray. When it’s dry, this helps to restore the faded plastic to its original black colour. Below you can see the two halves of the front handguard, on the left, after this treatment and on the right, before.
It may not be particularly obvious in this photo, but in real life, the difference is quite dramatic. All the plastics get the same treatment.
Then, it all gets reassembled. And I’m quite happy with how it turned out. It’s surprising just how much difference careful cleaning and touching up the rusty bits makes. This elderly M4A1 isn’t perfect by any means, but it is significantly better than it was.
The last stage is adding the carry-handle and rear sight. This replica didn’t come with either – it was fitted with a Swiss Arms red-dot reflex sight that I have decided to use on my Umarex G36. However, I was very happy to discover that it’s fairly easy to find replacements – I was able to source a generic Gexgune M16/M4 airsoft carry-handle and rear sight on Amazon for under €15.
It’s nicely made, fits well, incorporates elevation and windage adjustment for the rear sight and it matches the colour and finish of the rest of this replica. With this in place, it’s finally time to try some shooting.
After all this work, I’m keen to find out how well this elderly AEG shoots. And the answer is: very nicely indeed! It has much more power than my Umarex G36C and it’s more accurate too. The Umarex AEG isn’t bad, but it does produce occasional flyers than hit the target at anything up to 2” from the main group. This one produces tighter groups at the ranges at which I shoot and the adjustable rear sight means that I can get the point of aim and point of impact to coincide.
The result of around 50, 0.2g BBs, from 10m in a mix of semi and full auto.
Problems? Well, very occasionally the trigger seems to jam in while in semi-auto mode, but flipping it to full-auto and back fixes this issue. The spring that retains the collar at the base of the handgrip seems much too powerful. Pulling it down to remove or replace the upper handguard halve takes a lot more effort that I’d have liked. And the Hi-Cap magazine rattles like a maraca when it’s full of BBs.
That’s about it really. I really don’t like peep-sights, but that’s just what you get with an M4 and I can always replace the iron sights with the red-dot sight I got when I bought this. The rate of fire in full-auto is fairly slow because I’m using the 7.4v battery from my Umarex AEG rather than the recommended 9.6v. However, I don’t find that a problem at all and, to me at least, this slower rate of fire sounds and feels more realistic than the rapid “Brrrr…” that some AEGs produce in full-auto.
I was nervous about buying an old AEG that wasn’t working, but relieved to find that refurbishing it was fairly simple and no more complicated than working on any other replica. I have enjoyed this project and I have even learned a little about how AEGs work, which can’t be bad. In addition to the initial price of €20, the only cash I spent here was on the new carry-handle/rear sight assembly, and even that was easy to find and relatively cheap. I could buy a more powerful battery and charger and replace the Hi-Cap magazine this came with for a Low or Mid-Cap, but do you know what? I don’t think I’ll bother. I’m quite happy with it as it is and I plan to just enjoy shooting it for the moment.
For not a great deal of effort I have ended up with a functioning AEG that’s fun to shoot and doesn’t look too bad as a replica of the iconic M4. This King Arms M4A1 has good weight (just over 2.9kg with batteries and the carry handle in place), looks convincing and shoots well. For a total outlay of just €35, I’m happy with the result of this project. If you are offered an old AEG that needs a little TLC and you’re willing to put in a little effort, perhaps it might be worth considering?